As reported to the FAA. Reports are unverified, and codes are left as the FAA publishes them.
What was found
UNABLE TO MAINTAIN CABIN PRESSURIZATION. OUTFLOW VALVE INDICATED FULL CLOSED IN THE AUTO MODE. *S/D* ACCOMPLISHED FUSELAGE LEAK CHECK AND FOUND THAT THE FLEXIBLE PRESSURE SEAL AT THE PRESSURE BULKHEAD HAD BLOWN. THE FLEXIBLE RUBBER BOOT WAS REPLACED. PRESSURIZATION WAS NORMAL AFTER THE BOOT REPLACEMENT.